Sean ended up leaving with the absolute last person anyone expected.
The second that tall figure in sweeping black robes showed up, Harry and Ron swore they could already hear Gryffindor losing House points.
"Sean said he was staying at school for a month and a professor would come pick him up, but nobody said it was going to be Professor Snape…" Ron hissed, ducking deeper into the shop's shadow as Snape stalked toward them.
"Harry, I'm so glad you didn't put in for summer stay. Dodged a Bludger there, mate."
Harry just shrank lower. He still had no clue why Snape had protected him from Quirrell last year, and he had even less clue why the man seemed to hate his guts. Snape was one giant walking enigma.
"You two do realize staying over the summer isn't something they just hand out like Chocolate Frog cards, right?" Hermione snapped, even though she was shocked too. "Sean is literally the first student in a hundred years to get approved!"
"Yeah, well, he's also the future greatest—" Ron started, then slapped a hand over his mouth.
"What?" Hermione pounced.
"N-nothing!"
Hermione gave him a suspicious glare, huffed, and turned away.
Out on Diagon Alley's main street, the two professors locked eyes like they were performing some secret handover ritual.
"He's in the middle of the Animagus process, Severus," McGonagall said calmly.
"I know."
"Everything up to the thunderstorm step…"
She started to hand over a slip of paper, but Snape cut her off.
"I'll take it from here."
He snatched the note like it was his by right.
"I'll bring him back in two weeks—or on the night of the storm."
McGonagall repeated the words slowly. She was suddenly regretting promising Marcus she'd stay an extra two weeks.
They hadn't spent real time together in years, but somehow the places that needed her now went way beyond Hogwarts… and way beyond the old McGonagall house.
Sometimes "home" moves with the people you love.
"As for the Felix Felicis—you decide when to tell the boy," she added, then turned and walked off without looking back.
Snape spun on his heel and strode away. Sean hurried to keep up.
"Some idiots wouldn't know a good opportunity if it bit them on the nose. Wouldn't you agree, Mr. Green?" Snape said in his usual silky, poisonous tone.
"Does that mean I finally get to drink Felix Felicis?"
A calm, adult voice came from the badge on Sean's chest.
Snape jerked his head down and glared at the pin like it had personally insulted him.
"…Hmph."
He stared at it for another second, then spoke again.
"What exactly did you lot see on the fourth floor?"
"Voldemort."
Sean quickly tapped the badge to shut it up.
Snape froze mid-step. Rage poured out of his eyes; his voice actually shook.
"Ah yes—our own Mr. Sean Green, who thinks a couple of childish little spells make him some kind of hero… who apparently doesn't even fear the Dark Lord himself…"
The icy sarcasm dripped like venom.
"Excellent. Then, to reward your stunning bravery, your detentions will begin on September first and run until… September first… no holidays… and—"
Sean stopped walking. Snape wasn't finished.
"Every single year."
Sean blinked.
Wait… he had to stay at Hogwarts every summer from now on?
…Was this supposed to be a punishment?
When they finally got back to the castle, the sky was pitch black.
Snape was in the foulest mood imaginable. He couldn't even think about what was coming next.
The Dark Lord was plotting his return, and everyone knew what happened to wizards who got in his way.
He'd assumed the Green kid was just the organizer of whatever stunt they'd pulled, not that he'd faced Voldemort himself.
"And exactly what did you do? Tell me—every single detail!"
Down in the dungeons, Snape threw up every anti-eavesdropping spell he knew and snarled at Sean.
Sean let the badge give a very edited version: Quirrell acting weird, the cry for help, and Dumbledore finally driving Voldemort out of Quirrell's body.
The badge couldn't lie outright (it would blurt out the thought process behind any lie), but Sean could carefully choose what to mention and what to leave out. He downplayed his own role as much as possible.
"Do you have any idea who you are? Do you have any idea who you messed with? The arrogance is laughable!"
Snape was practically roaring.
A wave of retroactive terror hit him. Voldemort had walked into Hogwarts wearing Quirrell like a meat suit, and the ones who stopped him were a bunch of kids who'd stumbled into it.
And the reason? This idiot wanted to "help Quirrell"?
Because of one stupid recommendation letter?
Snape's shaking suddenly calmed. He stared down at the small boy who barely came up to the desk, at those rare green eyes glowing in the dim dungeon light, and for once he was speechless.
He was… too stupid for his own good. People that stupid never lasted long.
"Get out," he finally snapped.
The second the words left his mouth, thunder rumbled in the distance and a flash of lightning split the sky.
"Get back here!"
Snape bellowed it like he wasn't even sure who he was mad at anymore.
The storm had arrived.
Through the cracks in the dungeon ceiling they could see the bruised, angry sky.
Sean felt it—a second heartbeat, stronger than his own.
This was the moment he'd been waiting for.
The instant lightning cracked again, he had to sprint to wherever he'd buried the crystal phial. If he'd done every step perfectly, there would be a single mouthful of blood-red potion waiting inside.
"Where did you bury it?" Snape barked. The storm had come way too fast.
"The note, Professor…"
Snape suddenly remembered the slip McGonagall had handed him. Knowing Minerva's paranoid style, it would be somewhere he knew well.
He unfolded the paper—and froze at the glaring name.
Spinner's End.
He stood rooted to the spot. During summer holidays he almost never went back there. Minerva sometimes sent owls to stay in touch, but that didn't mean he wanted anyone else poking around his childhood home.
"Follow me. Now!"
He dragged Sean out of the castle at a run.
This idiot really was different, after all.
Night. Wind howling. Rain lashing sideways.
The hills around Hogwarts blurred into darkness; the castle itself was nothing but a black shape against the storm.
The only light came from the faint Lumos on the tip of Sean's wand as they fought their way forward.